Will Earth Survive When the Sun Becomes a Red Giant?

Since the beginning of human history, people have understood that the Sun is a central part of life as we know it. It’s importance to countless mythological and cosmological systems across the globe is a testament to this. But as our understand of it matured, we came to learn that the Sun was here long before us, and will be here long after we’re gone. Having formed roughly 4.6 bullion years ago, our Sun began its life roughly 40 million years before our Earth had formed.

Since then, the Sun has been in what is known as its Main Sequence, where nuclear fusion in its core causes it to emit energy and light, keeping us here on Earth nourished. This will last for another 4.5 – 5.5 billion years, at which point it will deplete its supply of hydrogen and helium and go through some serious changes. Assuming humanity is still alive and calls Earth home at this time, we may want to consider getting out the way!

The Birth of Our Sun:

The predominant theory on how our Sun and Solar System formed is known as Nebular Theory, which states that the Sun and all the planets began billions of years ago as a giant cloud of molecular gas and dust. Then, approximately 4.57 billion years ago, this cloud experienced gravitational collapse at its center, where anything from a passing star to a shock wave caused by a supernova triggered the process that led to our Sun’s birth.

Basically, this took place after pockets of dust and gas began to collect into denser regions. As these regions pulled in more and more matter, conservation of momentum caused them to begin rotating, while increasing pressure caused them to heat up. Most of the material ended up in a ball at the center while the rest of the matter was flattened out into a large disk that circled around it.

Young stars have a disk of gas and dust around them called a protoplanetary disk. Out of this disk planets are formed, and the presence of water ice in the disc affects where different types of planets form. Credit: NASA/JPL-Caltech

The ball at the center would eventually form the Sun, while the disk of material would form the planets. The Sun then spent the next 100,000 years as a collapsing protostar before temperature and pressures in the interior ignited fusion at its core. The Sun started as a T Tauri star – a wildly active star that blasted out an intense solar wind. And just a few million years later, it settled down into its current form.

Main Sequence:

For the past 4.57 billion years (give or take a day or two), the Sun has been in the Main Sequence of its life. This is characterized by the process where hydrogen fuel, under tremendous pressure and temperatures in its core, is converted into helium. In addition to changing the properties of its constituent matter, this process also produces a tremendous amount of energy. All told, every second, 600 million tons of matter are converted into neutrinos, solar radiation, and roughly 4 x 1027 Watts of energy.

Naturally, this process cannot last forever since it is dependent on the presence of matter which is being regularly consumed. As time goes on and more hydrogen is converted into helium, the core will continue to shrink, allowing the outer layers of the Sun to move closer to the center and experience a stronger gravitational force.

This will place more pressure on the core, which is resisted by a resulting increase in the rate at which fusion occurs. Basically, this means that as the Sun continues to expend hydrogen in its core, the fusion process speeds up and the output of the Sun increases. At present, this is leading to a 1% increase in luminosity every 100 million years, and a 30% increase over the course of the last 4.5 billion years.

The life cycle of a Sun-like star, from its birth on the left side of the frame to its evolution into a red giant on the right after billions of years. Credit: ESO/M. Kornmesser

Approximately 1.1 billion years from now, the Sun will be 10% brighter than it is today. This increase in luminosity will also mean an increase in heat energy, one which the Earth’s atmosphere will absorb. This will trigger a runaway greenhouse effect that is similar to what turned Venus into the terrible hothouse it is today.

In 3.5 billion years, the Sun will be 40% brighter than it is right now, which will cause the oceans to boil, the ice caps to permanently melt, and all water vapor in the atmosphere to be lost to space. Under these conditions, life as we know it will be unable to survive anywhere on the surface, and planet Earth will be fully transformed into another hot, dry world, just like Venus.

Red Giant Phase:

In 5.4 billion years from now, the Sun will enter what is known as the Red Giant phase of its evolution. This will begin once all hydrogen is exhausted in the core and the inert helium ash that has built up there becomes unstable and collapses under its own weight. This will cause the core to heat up and get denser, causing the Sun to grow in size.

It is calculated that the expanding Sun will grow large enough to encompass the orbit’s of Mercury, Venus, and maybe even Earth. Even if the Earth were to survive being consumed, its new proximity to the the intense heat of this red sun would scorch our planet and make it completely impossible for life to survive. However, astronomers have noted that as the Sun expands, the orbit of the planet’s is likely to change as well.

When the Sun reaches this late stage in its stellar evolution, it will lose a tremendous amount of mass through powerful stellar winds. Basically, as it grows, it loses mass, causing the planets to spiral outwards. So the question is, will the expanding Sun overtake the planets spiraling outwards, or will Earth (and maybe even Venus) escape its grasp?

K.-P Schroder and Robert Cannon Smith are two researchers who have addressed this very question. In a research paper entitled “Distant Future of the Sun and Earth Revisted” which appeared in the Monthly Notices of the Royal Astronomical Society, they ran the calculations with the most current models of stellar evolution.

According to Schroder and Smith, when the Sun becomes a red giant star in 7.59 billion years, it will start to lose mass quickly. By the time it reaches its largest radius, 256 times its current size, it will be down to only 67% of its current mass. When the Sun does begin to expand, it will do so quickly, sweeping through the inner Solar System in just 5 million years.

It will then enter its relatively brief (130 million year) helium-burning phase, at which point, it will expand past the orbit of Mercury, and then Venus. By the time it approaches the Earth, it will be losing 4.9 x 1020 tonnes of mass every year (8% the mass of the Earth).

But Will Earth Survive?:

Now this is where things become a bit of a “good news/bad news” situation. The bad news, according to Schroder and Smith, is that the Earth will NOT survive the Sun’s expansion. Even though the Earth could expand to an orbit 50% more distant than where it is today (1.5 AUs), it won’t get the chance. The expanding Sun will engulf the Earth just before it reaches the tip of the red giant phase, and the Sun would still have another 0.25 AU and 500,000 years to grow.

Artist’s impression of a Red giant star. Credit:NASA/ Walt Feimer

Once inside the Sun’s atmosphere, the Earth will collide with particles of gas. Its orbit will decay, and it will spiral inward. If the Earth were just a little further from the Sun right now, at 1.15 AU, it would be able to survive the expansion phase. If we could push our planet out to this distance, we’d also be in business. However, such talk is entirely speculative and in the realm of science fiction at the moment.

And now for the good news. Long before our Sun enters it’s Red Giant phase, its habitable zone (as we know it) will be gone. Astronomers estimate that this zone will expand past the Earth’s orbit in about a billion years. The heating Sun will evaporate the Earth’s oceans away, and then solar radiation will blast away the hydrogen from the water. The Earth will never have oceans again, and it will eventually become molten.

Yeah, that’s the good news… sort of. But the upside to this is that we can say with confidence that humanity will be compelled to leave the nest long before it is engulfed by the Sun. And given the fact that we are dealing with timelines that are far beyond anything we can truly deal with, we can’t even be sure that some other cataclysmic event won’t claim us sooner, or that we wont have moved far past our current evolutionary phase.

An interesting side benefit will be how the changing boundaries of our Sun’s habitable zone will change the Solar System as well. While Earth, at a mere 1.5 AUs, will no longer be within the Sun’s habitable zone, much of the outer Solar System will be. This new habitable zone will stretch from 49.4 AU to 71.4 AU – well into the Kuiper Belt – which means the formerly icy worlds will melt, and liquid water will be present beyond the orbit of Pluto.

Perhaps Eris will be our new homeworld, the dwarf planet of Pluto will be the new Venus, and Haumeau, Makemake, and the rest will be the outer “Solar System”. But what is perhaps most fascinating about all of this is how humans are even tempted to ask “will it still be here in the future” in the first place, especially when that future is billions of years from now.

Somehow, the subjects of what came before us, and what will be here when we’re gone, continue to fascinate us. And when dealing with things like our Sun, the Earth, and the known Universe, it becomes downright necessary. Our existence thus far has been a flash in the pan compared to the cosmos, and how long we will endure remains an open question.

Oh yeah, push the earth out to a safe distance. Not. Life on earth will end as soon as the asteroid belt is jumbled up and meteors come screaming in from every direction. There won’t be a safe hole in the solar system to hide.

Seriously though, who knows what will happen to the human race in a billion years. By that time, we will at least have a greater understanding of what can be done, if anything, to save our planet. Or perhaps we will have evolved, or moved on to another star system. One thing that all of us can do to prepare is buy as many shares in Coppertone as we can.

I am not sure of that but the earth don’t have the sufficient energy to go so far in the space also the space is very hostil place, but may be that could pass too, but I am not so sure this will be event will happen? ❓

I’m glad you have a mind that is interested in these sort of things. You a little mistaken on the effects of gravity, and Relativity, but that OK, There’s plenty of time to learn more. You might want to read up on Issac Newton’s Laws of Motion and Gravity, as well as Albert Einsteins Theories of General and Special Relativity. It’s pretty heady stuff to be reading though, even for those with an understanding of it. Not for the faint of heart, but I encourage you to learn more.

One question I did forget to ask, is there a way (theoretical) to stop a sun from becoming a red giant? Correct me if I’m wrong, but doesn’t this happen when the star’s fuel source (ie: hydrogen) runs low? How might we “fill the tank up again”?

no its not actually it is said that the earth will be pulled towards a less massive sun wen our sun is expanding, but life on earth will be different so will animal life but thi sis 90% possible this is from scientist

n binary systems this can happen in some rare occasions. A white dwarf can strip the matter from a companion giant until it achieves sufficient mass to re-initiate it’s core fusion process. This has been observed already. @Ellen. Gravity is what holds all the planets in place. Not just the Sun’s gravity, but all the individual planets, and well as their individual and collective gravitational effect(s). The Sun’s gravity pulls the Earth towards it. The Earth’s gravity tries to pull back. At some point. The two gravitational effects will cancel out in a “Lagrangian Point” (look it up), and the two objects will fall into a nice orbit around each other. Locked in a long orbital dance that literally lasts a lifetime. If the Sun’s mass is reduced, that means the pull on the Earth will be less, allowing the Earth, and well as the other planets and objects in our solar system to drift farther away.

In binary systems this can happen in some rare occasions. A white dwarf can strip the matter from a companion giant until it achieves sufficient mass to re-initiate it’s core fusion process. This has been observed already. @Ellen. Gravity is what holds all the planets in place. Not just the Sun’s gravity, but all the individual planets, and well as their individual and collective gravitational effect(s). The Sun’s gravity pulls the Earth towards it. The Earth’s gravity tries to pull back. At some point. The two gravitational effects will cancel out in a “Lagrangian Point” (look it up), and the two objects will fall into a nice orbit around each other. Locked in a long orbital dance that literally lasts a lifetime. If the Sun’s mass is reduced, that means the pull on the Earth will be less, allowing the Earth, and well as the other planets and objects in our solar system to drift farther away.

Most likely we will have maneuvered asteroids into new orbits around the Earth such that they will impart orbital energy to the Earth and push its orbit out artifically. The moon would probably be lost, unless some effort is made to save it as well. Of course any miscalculation would likely result in a catastrophic asteroid impact. Also we are assuming that mankind has not already driven itself to extinction and we survive that long.

I suspect Schroder and Smith are nearly 100% correct in their projections. The bigger more interesting question is will humans still be around to witness this solar expansion? Probably not unless some heretofore yet undiscovered phenomenon is exploited before the expansion that will allow practical space travel and colonization. Based on current developing propulsion technology, a space vehicle sent to the solar system’s nearest neighboring star will span thousands of generations traveling in space. It is challenging to wrap your mind around the chances of survival for an evacuation effort on the scale needed for human survival. The distances are simply too great and the human too fragile.

Seriously… if there are humans around in 4-5 million years they won’t be anything like we are now (e-v-o-l-u-t-i-o-n!!)….. You guys are talking about BILLIONS of years in the future!!! This is all speculation anyway but I bet there won’t be “humans” (like we know them) around to care….

Believe me human beings should not be worried about the future far far in billion years because there are lot of other resources to completely destroy our planet within just next 1000 years. Human beings have not been on the planet even for the last million years and we are thinking about billions!! waste of time. The planning of Human beings can work only upto 200 years in advance and after that every thing is upto nature. All the calculations will finally be proven wrong and our future generations will call us fools and ignorant ancients.

I’ll have to agree with Andrew. We’ve nearly done away with natural selection so our evolution won’t continue in the “classic” sense. We as a species may even have lost the ability to adapt to gradual changes in our environment, let alone the rapid changes we’re causing ourselves. So in all likelyhood, humans will be extinct in substantially less than the timescales talked about in the article.

Lam “Based on current developing propulsion technology, a space vehicle sent to the solar system’s nearest neighboring star will span thousands of generations traveling in space.”

I think you are off by several orders of magnitude on the time required. With current technology, 1/10 c is possible for an unmanned no deceleration probe to A. Centauri. Allowing a conservative 1/100c for a generation ship and 33 years per generation, it’s still only 12 generations. Even at 1/1000c, or 186 miles per second, only 120 generations are required. For reference, low Earth orbit satellites move at about 5 miles per second.

I disagre with the idea that humans have or will stop evolveing. Instead of adapting to the natural world we will adapt to the artifical one we create. However sence we design our artifical environments to sute how we are now I could, in retrospect, expect a slowdown in evolution.

But sence tha average lifespan of all previous hominid species is only 250,000 years this may all be a little academic.

Evolution is not adaption. It is a change in gene frequency in response to selective pressures, and because human society protects those individuals who would normally be selected out we have essentially stopped our natural evolution. We won’t design artificial enviroments to be selective because that goes against basic human morality. You just don’t design something which selectively kills or makes infertile a certain group of people. It’s just not cool.

This is not to say that we cant’ change technologically, socially, ethically or even change physically but this will not be an evolutionary change.

One thing I forgot though is susceptibility to disease, which is still a selective pressure in places that lack proper medication.

In response to the question by Brian – is there any way of stopping the Sun from becoming a red giant? The answer is yes. It will need to be fully mixed and reduced in mass over time. The Sun starts to become a red giant after consuming only about 1/10th of its total hydrogen supply, so the mixing allows it to convert all of its hydrogen into helium. The mixing also stops the Sun from swelling up into a giant star. The mass loss is needed to reduce the luminosity increase with age.

With shameless advertising a book on this topic has recently been published by Springer called Rejuvenating the Sun and avoiding other global catastrophies (buy and enjoy).

Actually, there is considerable evidence that human evolution is proceeding at a faster rate today than it did 10,000 years ago. Because the Earth is now over-populated with humans, the number of minor genetic mutations per time period is substantially higher than it was thousands of years ago. And because of over-population, the opportunities for those mutations to be passed on to new generations are much greater.

yea like the human race is goin survive that long…. the dinosaurs were aronud for millions of years and we hav been here for the blink of an eye in astronomical terms and already set about destrying our home… we are already past the point of no return,… Im worried for the future of my children, but they dont seen to care.! RAy

[When the Sun does begin to bloat up, it will go quickly, sweeping through the inner Solar System in just 5 million years. It will then enter its relatively brief (130 million year) helium-burning phase]

The above does not match with: [But the habitable zone will be gone much sooner. Astronomers estimate that will expand past the Earth’s orbit in just a billion years.]

“When the Sun does begin to bloat up, it will go quickly, sweeping through the inner Solar System in just 5 million years. It will then enter its relatively brief (130 million year) helium-burning phase” – these seem consistent with the other figures – millions not billions

“The above does not match with: [But the habitable zone will be gone much sooner. Astronomers estimate that will expand past the Earth’s orbit in just a billion years.]” – this is about how the habitable zone of the solar system changes while the Sun is still in it’s Main Sequence phase – long before the final Red Giant convulsions. The full article declares that the Sun’s luminosity will increase 10% in the next billion years – making it too hot for us here! Mars might be quite comfortable. The Sun will still be pretty much the same diameter as it is now.

It is romantic to think our species will be around in some form at that future time, and will have adapted and evolved to a point where we can escape to a safe haven.
However , we evolved here with the sun as our life force, I think , if we are still here , it is fittng that our evolution comes to an end when the sun reaches its evelutionary end. Isn’t many billions of years (if we are very lucky) more than enough for any species?

To put future billions of years in perspective, in less than one tenth that time in the past, our most highly evolved ancestors were one celled microbes. Species normally survive only one or ten million years before going extinct. Man is a species. Our tendency is to assume that we will live longer because . . . and we find a because that suits our emotions.

As for not evolving any more, somewhere recently I read a magazine article, Time or Discover or some such, that made Gerald McKeeganâ€™s case that the human race is presently evolving 160 times faster now than it was in the past. Yeah, it surprised me too, even though the Darwin Award winners remind me that some people today are hell bent on improving the gene pool.

Last thought. You cannot extend the life of the sun by adding mass. That would shorten its life because it would then burn its total fuel supply faster.

Don’t forget Andromeda! Much before the sun bloating up, there could be a galactic collision with our neighbour, which might even throw us out of the Milky way. Everything would be changed. The sun may be orbiting a black-hole or some other supergiant. We need a real megasuper computer to calculate all that. Hence a second revisit!

How this affects us humans is a moot point. We most certainly will not be here, either cuz it isn’t us, or because we’ve moved on. It will destroy our history though ): However, that will happen much, much sooner when the sun warms up in some 500 million years. Only a tiny portion of humanity has to survive to keep us genetically viable and allow the species to continue to live and evolve. Think of the ships, giant solar sails flying, heading out on the solar wind from our burgeoning red giant sun. And as for Alpha Centauri, who’s to say IT will still be around? That’s one hell of a long time. Let’s do some quick math…(just in case) A.Centauri at 4 light years…therefore 4 years at light speed, 40 years at 1/10 light speed. Chuck Lam…how fast do you think we’ll be going in half a million years, let alone 7 billion? You scoffed at 120 generations…that’s 2400 years! That’s only 1/600th the speed of light. I tried to work out acceleration of 1 g for 20 years turning around at mid trip and decelerating for the rest but even though it gave me some odd numbers, it did suggest that we could make it to a substantial portion of c and therefore enjoy some time dilation on the way! Like a 40 year mort-gage BUT paid off BI-weekly!

Sun will heat up as it ages during it’s life as a main sequence star, in mere millions (let alone billions) it will be far too hot to survive on this planet. Hopefully by then we will have technology comparable to the forerunner in “Halo” and moving planets around and terraforming, even making new worlds to live on would be trivial; but it’s more likely we’ll kill each other before then, in a matter of centuries, if not decades.

This is really stupid of people, y r we worring about something the human race might not even get a chance to experience, i mean we do have billions of years to evolve.We might turn into something brainless, and by the way i do think that we will kill r selfs before this has a chance to happen.We’ll sooner or later start a nuclear war or maybe global warming will turn everthing into deserts, like wat happened to the creatures before the dinosaurs (everthing turned to deserts, killing 99% of the earths creatures)

ohh and one more thing even if we have the tech. to avoid the sun, it will still vaporize every ocean on the planet.And if we hav the tech to avoid it by a long shot then the sun will sooner or later going to die and turn into a black hole and everyone knows we can live without sunlight.The only way we can survive is to find a terastrial planet and try to get to it and live in it.

No!!! We Must survive!!! After all, since all other possible intelligent life out there is supposedly super friendly, the universe needs and intelligent specie to rise to power and make life miserable for them all. The way so many talk, I think it means we are the best candidate to make that happen, right?

So, we must survive if only to make other aliens miserable!!! Muwhahahah!!!

i know i wont proberly live to see the world end be it war, global warming, exploding sun but if i do i would be so glad. Think about it the human race is one hell of an evil race we have mass murded fellow humas for beliving something different we invade countrys for its oil and in the process kill others. These are so small topics in the universe if aliens visted us and we told them we were on the verge of necular war they would proberly laugh at us and why aliens even want to vist us any way were rude, greedy stupid.

Long before our planet goes into the first of many final stages, human technology has created spacecraft for emigration to other planets. An including all the means for developing a biological, that is, real life. I am quite convinced about this. But it is a sad fact to encounter, for all of us: the death of Tellus. The fragile frame of our lives here on earth, the very short time we exist, is a sad fact. Existence is, on the other hand, a wise construction or creation: when we have lived, we go to rest again. This is, for me, a proof of a divine force behind it all. Rest is peaceful sleep forever. Creating love and humane conditions on earth is our timeless task. Never lose your hope. Life is too precious.

ALL CAN SAY IS GOODBYE TO EVERYONE AND THE PEOPLE THAT SAY WE COULD DO LOADS OF THINGS IN THE FUTRE WELL YOU NEVER NO IF WE COULD ALSO WE MAY NOT EVEN LIVE BECUASE THE DEADLY ATEROID THAT WILL HIT US IN 2029 OR 2036 HPE YOU LIVE PEACEFULLY

i bet the sun is gettin bigger every decade or so. man! i wish the universe didn’t have to go down so bad i wish. to bad i won’t be able to see the earth die or survive. plus it will take a long time to go to a solar system similar to or the milkay way. maybe we can use that theory it’s called, Attackons. it can go way faster than light travel. it would take 100 million years to reach the cloest star ever!!!!!!!!! man those scenitists better act fast so we can live on a planet just like earth. mars!! are u kiddin me! no way hosa i ain’t gonna die because of that sun destroyin those inner planets.

Travon,.. why you gotta be a hater. True it is gods plan, but that doesn’t means existence will end. After all, during the beginning of sun’s transformation human beings should adapt to the constantly rising temperatures. Just perhaps we won’t have to leave earth will might just aquire the ability or organs to breathe with no oxygen or possibly survive in the earth’s crust like mole men. Also, I think that deep down inside no nation is crazy or insane enough to launch a nuclear attack. Humans will eventually realize that the idea of wiping out whole nations is an unreasonable and unwanted resolution to win a war or obtain resources.

Technology will be modified to deal with these circumstances. I think that once humans realize that their all about to die in a twisted dry death. All nations will unite and an amazing invention will be forged from the minds of top scientists around the planet. Perhaps the Earth will develop their once custom made atmosphere to protect against the heat and provide oxygen. Maybe a giant rocket would be built on earth to launch the earth many billions of light years away to safe haven in another galaxy. Although i am not sure which will happen I have foreseen the earth’s survival in meditation. God’s speed to you all! *BD*

I doubt humans will become extinct, we’ve so far in such a short amount of time, makes you really appreciate the human capacity to advance.

Human’s might be destructive in nature, but I believe that’s because we’re meant to be, a huge part of our technological advancement has come about through conflict, I’d go so far as to say WE NEED IT. An example I like to use is Velcro:

Hmmm.. billions of years from now we will have evolved into a new species.. more intelligent I hope. possibly not even needing a physical body. Yes we are evolving… getting taller, more people with not enough room on their jaw for wisdom teeth.
We will have either destroyed ourselves, been destroyed by an asteroid or comet impact, or we would have conquered space itself and spread through at least the galaxy if not even to other galaxies in the next few million years. No need to worry about our sun expanding into a Red Giant.

Well, I think that no human beings will ever survive the problems today coz after every species of every kind and every drop of water(drinkable water is just .5%!!) is gone, there is NO food, NO water and NO clean air to breath with. How can we be able to survive that? It would be a miracle. I think we wont be able reach that phase of life on Earth.

All you people worrying, read it carefully.
We will all be dead and no one will be alive when this happens, its states that even before the Sun is close to us, the Earth will be inhabitable in the first place, and this is 7.59 billion years away, even more. Because 7.59 billion years is when they estimate it to start. So don’t worry!

All you people worrying, read it carefully.
We will all be dead and no one will be alive when this happens, its states that even before the Sun is close to us, the Earth will be inhabitable in the first place, and this is 7.59 billion years away, even more. Because 7.59 billion years is when they estimate it to start. So don’t worry!

We will cohabit an outer planet before then.. but for how long ? By that time, human knowledge and tech will be in the soler system somewhere, until we can’t go no further. That’s where real survival will start in earnest !!

Hmmm. Just asking the solar scientists out there. I wonder if the expanding sun would create enough outward pressure to overwhelm current orbits and re-position the Earth (and other planets); and the Earth would remain in a new life support zone (maybe a few more billion years)?

I love stories like this one. Lets try to scare people to read the story.

1st off, the earth will already be gone by that time. The ozone is going to be gone in a couple thousands years at the most according to the Climate idiots. So the suns heat will burn it up long before it turns in to a red giant. I guess it is already an orangey/ yellow giant already if not a red giant.

2nd, an asteroid will destroy earth or should I say Haley’s comet before this happens.

3rd, for all we know the sun already went super nova according to some of these scientist but we will not know for a while since it takes so long for the light to get here

4th, Independence day will happen by then and Will smith will not be around to save us.

The Moon moves farther from the Earth every year. Is it possible that the Earth does the same in relation to the Sun?

If so, is it possible that the Earth will have moved substantially farther from the Sun in 4 billion years? I’m not suggesting the Earth will be in a habitable zone, just wondering about the relative positioning.

it wont really matter. By the time the sun is a red giant, we humans will have long ago used up every natural resource this planet has to offer. We will have chewed it up, spit it out, and moved on to another solar system. That is if we haven’t all perished due to natural or man-made disasters (disease, asteroid impacts, nuclear war, etc…).

Numbers of enormous proportions have always amazed me, and I have spent a lot of idle time contemplating…things like trying to imagine the time of the dinosaurs 65,000,000 years ago, or the distance from earth to the closest galaxy. Just incomprehensible. What is even more incomprehensible is believing that humans will exist in a mere 100,000 years. Just unimaginable. It wont happen. We will destroy our selves along with everything else on the planet.

actually its said that the earth will be pulled towards a less massive sun when our sun is expanding according to scientists that is 50% possible, and they sauy that life will be more advanced that humnas will be greater in knowledge Keep up the hope!

A very old article it looks like. Explains why the science is off a bit. The The Sun won’t expand because of loss of mass, but in fact loss of Gravity (due to the effects of Relativity it’s technically the same thing, but not quite in solar effects)). Since the Andromeda Galaxy is Crashing head on into the Milky Way at a near right angle to each other at about 250,000MPH. That means in 2.6 billion years, the sky will be full of new stars from Earth’s perspective, and the resulting “crash” (merger actually) of the two galaxies will be casting solar systems left and right in all directions, Later to collect them back up into a new Galaxy after the SMBH at the center of each of the two galaxies merge. Rolling the time frame back more, because mankind will already be dead long before that happens due to the massive solar winds in the next 750 million -1.25Billion years heating up the Earth, sterilizing all life on it’s surface, and incinerating it’s oceans and atmosphere. So you see. It’s an unproven tenant, and always will be, because……we will all be dead. BTW: Once the Sun exits it main sequence stages, and then does it’s expansion and collapse phase. It will burn it’s helium core for likely the life of the Universe as a white dwarf. Theoretically, if it gets pushed (slung, tossed, whatever) into an area of space where gas and nebular dust are plentiful, it could possibly roar back to life someday as a new Sun.